Estimate and validate an IHG model for given ordinal responses, with covariates to explain the preference parameter.
ihgcov(m, ordinal, U)
An object of the class "IHG"
An object of the class "IHG"
Number of ordinal categories
Vector of ordinal responses
Matrix of selected covariates for the preference parameter
The optimization procedure is run via "optim", option method="Brent" for constrained optimization (lower bound = 0, upper bound=1).